Cassandra why java

You can find the documentation for latest version through Java driver docs or via the release tags, e. A modern, feature-rich and highly tunable Java client library for Apache Cassandra 1. The driver architecture is based on layers. At the bottom lies the driver core. This core handles everything related to the connections to a Cassandra cluster for example, connection pool, discovering new nodes, etc. Feeback requested: help us focus our efforts, provide your input on the Platform and Runtime Survey we kept it short.

The last release of the driver is available on Maven Central. You can install it in your application using the following Maven dependency:. Connections to other hosts will only be opened when a session gets created.

You can also specify a keyspace name at construction time, it will be used as the default when table names are not qualified:.

You might be tempted to open a separate session for each keyspace used in your application; however, note that connection pools are created at the session level, so each new session will consume additional system resources:.

Also, there is currently a known limitation with named sessions, that causes the driver to unexpectedly block the calling thread in certain circumstances; if you use a fully asynchronous model, you should use a session with no keyspace. Finally, if you issue a USE statement, it will change the default keyspace on that session:. Be very careful though: if the session is shared by multiple threads, switching the keyspace at runtime could easily cause unexpected query failures.

Generally, the recommended approach is to use a single session with no keyspace, and prefix all your queries. As shown here, the simplest form is to pass a query string directly. You can also pass an instance of Statement. Executing a query produces a ResultSet , which is an iterable of Row. Note that this will return all results without limit even though the driver might use multiple queries in the background.

To handle large result sets, you might want to use a LIMIT clause in your CQL query, or use one of the techniques described in the paging documentation. When you know that there is only one row or are only interested in the first one , the driver provides a convenience method:. Row provides getters to extract column values; they can be either positional or named:. In addition to these default mappings, you can register your own types with custom codecs. To ensure type safety, collection getters are generic.

You need to provide type parameters matching your CQL type when calling the methods:. For nested collections, element types are generic and cannot be expressed as Java Class instances.

DataStax Java Driver 3. Another is security. Not having to worry about buffer overflows means most of the worst kind of security holes are simply impossible. Your impression is incorrect. Bearing in mind that Java is quite a productive language despite its naysayers and portable, together with the JIT optimisation capability, means that Java isn't an unreasonable choice for something like this.

The performance penalty for modern Java runtimes is not that big and programming in Java is less error-prone than in c.

Stack Overflow for Teams — Collaborate and share knowledge with a private group. Create a free Team What is Teams? Collectives on Stack Overflow. Learn more. Why was Cassandra written in Java? Asked 11 years, 8 months ago. Active 3 years, 6 months ago. Viewed 24k times. Improve this question. Stefan Steiger. Stefan Steiger Stefan Steiger IMO there is nothing inherently subjective and argumentative in this question. The wording "Why the hell" clearly needs improvement, but overall I think this is a valid question.

Hadoop is written in Java. Amazon's dynamo backend is written in Java. ScyllaDB is faster than Cassandra Benchmark and part of the reason as explianed in the architecture document is the way that the JVM works with the network stack.

Show 8 more comments. Active Oldest Votes. Hand coded assembly would be faster if you have a few decades to spare. Improve this answer. Martin Martin Hahaha, that answer was to be expected.